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          <th colspan="3" align="center"><span xmlns="http://www.w3.org/1999/xhtml" class="emphasis"><em>db</em></span> close</th>
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            <h2 class="title" style="clear: both"><a id="db_close"></a><span class="emphasis"><em>db</em></span> close</h2>
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      <pre class="programlisting">db close
	[-nosync]  </pre>
      <p>
         The <span class="emphasis"><em>db</em></span> <span class="bold"><strong>close</strong></span>
         command flushes any cached database information to disk, closes any
         open cursors, frees any allocated resources, and closes any underlying
         files.  Because key/data pairs are cached in memory, failing to sync
         the file with the <span class="emphasis"><em>db</em></span> <span class="bold"><strong>close</strong></span> or <span class="emphasis"><em>db</em></span> <span class="bold"><strong>sync</strong></span> command may result in inconsistent or lost
         information.
    </p>
      <p>
        The options are as follows:
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            <p>
                 <span class="bold"><strong>-nosync</strong></span> 
            </p>
            <p>
                 Do not flush cached information to disk.     
             </p>
            <p>
                 The <code class="literal">-nosync</code> flag is a dangerous option. It should only be set if the
                 application is doing logging (with transactions) so that the database
                 is recoverable after a system or application crash, or if the database
                 is always generated from scratch after any system or application
                 crash.
            </p>
            <p>
                 It is important to understand that flushing cached information to disk
                 only minimizes the window of opportunity for corrupted data.  Although
                 unlikely, it is possible for database corruption to happen if a system
                 or application crash occurs while writing data to the database. To
                 ensure that database corruption never occurs, applications must either
                 use transactions and logging with automatic recovery, use logging and
                 application-specific recovery, or edit a copy of the database; and
                 after all applications using the database have successfully called
                 <span class="emphasis"><em>db</em></span> <span class="bold"><strong>close</strong></span>,
                 atomically replace the original database with the updated copy.
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      <p>
         After <span class="emphasis"><em>db</em></span> <span class="bold"><strong>close</strong></span>
         has been called, regardless of its return, the DB handle may not be
         accessed again.
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      <p>
         The <span class="emphasis"><em>db</em></span> <span class="bold"><strong>close</strong></span>
         command returns 0 on success, and in the case of error, a Tcl error is
         thrown.
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